Expression of Matrix Metalloproteinases and Endogenous Inhibitors in Abdominal Aortic Aneurysm and Aortoiliac Occlusive Disease (Syndrome Leriche).

Matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) play a complex role in the pathogenesis of atherosclerosis. We compared (1) the histopathological findings in patients with abdominal aortic aneurysms (AAA) and aortoiliac occlusive disease (AOD); (2) the expression of MMP-2/MMP-9 and TIMP-1/TIMP-2 in aortic layers, inflammatory cells and smooth muscle cells (SMCs), aiming to identify the common underlying pathogenic mechanisms of the disease development. Samples were obtained from 30 patients with AAA and 30 with AOD. Aortic histology and immunohistochemistry were performed to evaluate inflammatory changes and MMP and TIMP expression. Thrombosis and ulceration were more frequent in AOD than in AAA. The MMP-9 expression was elevated in all aortic layers of AAA patients and in media/adventitia of AOD patients, mainly followed by lower expression of its inhibitor TIMP-1. Higher MMP-9 expression was also found in SMCs and macrophages of both AAA and AOD specimens, while higher TIMP-1/TIMP-2 were predominantly observed in the lymphocytes and macrophages of the aneurysm. These results showed that both conditions exhibited increased MMP-9 expression; however, the MMP expression pattern differed to some degree between the aneurysms and occlusive disease. The variations in molecular mechanisms underlying dilatative/stenosing disease warrant further investigation.

Stereologic parameters of nuclear ultrastructure as markers of the steroid receptor status in breast cancer epithelium.

The nuclear specific surface density (Sv/Vv), mean nuclear area (A) and numerical density (Nv) of tumor cell nuclei from 30 primary invasive female breast carcinomas with known concentrations of estrogen and progesterone receptors (ER and PR), were morphometrically analyzed at the ultrastructural level. It was found that carcinomas with concordant positive ER and PR status contained significantly higher number of smaller nuclei per volume unit of epithelium (mean Nv = 1.5 x 10(6) mm-3, mean A = 27 microns 2), than carcinomas of negative concordant receptor status (mean Nv = 0.8 x 10(6) mm-3, mean = 37 microns 2). Tumor cell nuclei of the former frequently displayed an elliptic shape (mean Sv/Vv = 1.16 microns-1), and had deeply invaginated surfaces, whereas nuclei of the latter were more frequently ball-shaped and exhibited a smooth-surface (mean Sv/Vv = 0.88 microns-1). The numerical density Nv (NUC/EPI) of tumor cell nuclei turned out to be a most reliable morphological marker of the concordant ER and PR status (overall efficiency = 84%, p < 0.01). The nuclear surface and volume ratio and mean nuclear area also appear to be reliable markers for terminal stages of the biochemical differentiation of breast carcinoma (overall efficiency = 79%, p < 0.05).

Individual differences between nuclear parameters of normal and malignant breast epithelium.

This study attempts to estimate the status of estrogen and progesterone receptors (ER and PR) in tissue of invasive breast carcinoma. Identical stereologic parameters of nuclear ultrastructure, of normal and malignant epithelium in the same breast were compared. Samples of normal and malignant epithelium of 30 surgically amputated breasts were analysed morphometrically. The concentration of ER and PR in the malignant epithelium was estimated by means of the dextran-coated charcoal (DCC) method. We measured the mean nuclear area (A), nuclear specific density (Sv/Vv) and nuclear numerical density (Nv) of epithelium. The comparison of such models of normal and malignant epithelium nuclear ultrastructure of the same breast demonstrated: a) the difference between Sv/Vv of nuclei very sensitively and specifically marks the ER status in malignant tissue (overall efficiency = 80%, p < 0.01), and b) the difference between A, Sv/Vv and Nv marks the concordant ER and PR status with identical overall efficiency. Minimal individual differences in size, surface structure and shape, observed between nuclei of malignant epithelium of positive concordant ER and PR status and nuclei of normal epithelium demonstrated that the highest morphological similarity is associated with biochemical similarity of cells exposed to the identical media of steroid hormones.

Definition of the optimum freezing rate-1. Investigation of structure and ultrastructure of beef M. longissimus dorsi frozen at different freezing rates.

The influence of freezing rate on location, shape and size of ice crystals formed during freezing of beef M. longissimus dorsi, as well as its influence on ultrastructure, were investigated. Muscle samples were frozen at different rates: 0·22 cm/h and 0·39 cm/h (cooling agent was chilled air), and 3·33 cm/h, 3.95 cm/h, 4·92 cm/h and 5·66 cm/h (cooling agent was liquid carbon dioxide which expanded in the sucking-pipe of the tunnel freezer). It was found that by slow freezing (freezing rates 0·22 cm/h and 0·39 cm/h) 30·00 µm). An increase in the freezing rate was followed by a change in ice crystal location. In this case they had also been formed intracellularly. The number of crystals increased while their size decreased. The most intensive fibre damage was found in samples frozen at a rate of 0·22 cm/h, and the least in samples frozen at a rate of 3·95 cm/h with a freezing temperature of -50°C.